Process for producing beta-aminonitriles and- beta-aminoesters



Patented May 2, 1.961

ever, on an absolute basis with amines having a higher number of carbon atoms such as nonylamine and higher, the yields still leave something to be desired. It has now been discovered that yields from these higher amines ca'n PROCESS g g i N 5 be materially increased by employing an N,N-dis ubstituted amide as a solubilizer for the water catalyst in the Phillip Montgomery, Texas City, and Roy p reaction of these amines with nip-unsaturated acid deriva- Galveston, Tex., assiguors to Monsanto Chemical tives. i 7 Company, St. Louis, Mo., a corporation of Delaware -According to the invention, tert-carbinamines of the 10 formula No Drawin Filed Au 23 1957 Ser. No. 680 005 g g 9 9 i kr ncNHz 7 Chums 260-4655) wherein R, R and R are chosen from the group consisting of alkyl, cycloalkyl, a-ryl, alkaryl and aralkyl radi- V cals containing from 1 to 12 carbon atoms are reacted The present invention relates to an improved method with a compound chosen from the group consisting of the for the production of certain types of amino compounds. lower aliphatic esters and nitriles of n p-unsaturated acids More particularly, it relates to the preparation of ,B-aminoin the presence of a catalytic amount of water and an nitriles and fl-aminoesters. N,N-disubstituted amide as a solubilizer thereforto yield It is well known that valuable amino compounds can the corresponding B-aminonitriles and fi-aminoesters. be obtained by the addition reaction eflected between The following examples are presented to illustrate the a,B-unsaturated nitriles and a nitrogen-reactive ammonia invention but are not to be construed as limiting it in any base such as ammonia, hydroxylamines, hydrazines, alimanner. phatic, hydroaroinatic or aromatic primary or secondary EXAMPLE I F polyamltnes g g i ig A series of experiments were made in which tent- Pnmary amine? p tea y W es ers o nonylamine and tert-pentadecylamine were reacted with rated carbolfyhc ac1d? Such methyl acrylate acrylonitrile. The nonylamine and pentadecylamine emample y1eld f .Generauy amines ployed were mixtures of isomers of essentially tert-carbinreact with a d-unsaturated acid derivatives of the acrylate amine structure obtained by Ritter reaction of type as the Iowa? ahphatlc esters i of pylene trimer and hydrogen cyanide and propylene acry ac1d methacryhc acid crqtomc wlth9ut pentamer and hydrogen cyanide, respectively. In one the of a catalyst .However this afidmn reactlon run, precautions were taken to-use substantially-anhydrous item: eflects are wry Important and {he and branch' reagents. In the second run, water was added as a catamg f the aikyl groups have a defimte Influence. on lyst and in the other runs an- N,N-disubstituted amide reactlon' example {eported for the t was added as a solubilizer with the water catalyst. The of acrylonitrile with tert-butylamine have been considerareactions were carried out in a 500ml round bottom P 9 than for the other butylamiries' This three-neck flask fitted with a 250-rnl. dropping funnel 5 in yield s even more pronounced with tert-octy a f thermometer a. stirrer a reflux condenser and a heating where the use of elevated temperatures, extended reaction mantle. Equimolary qllamities of the reactants were used 26 32 catalgsts f 'f g? i ymlds g g 40 The amine, amine and water, or amine, water and soluh f 0. a 5 g ys t 9 olvercomef bilizer, was charged to the flask, stirred, and heated to a 1 y as een escn e u P f o 6 temperature of about 80 C. Then the acrylonitrilewas amme {'eactant must, be tolerated If It 1 added dropwise from the funnel over a period of from Theonitlcanyz f n recovered by of about 15 to about 50 minutes. After addition of the the d de nvat1ve wlth 'PP Practlcauy, acrylonitrile was completed, the reaction mixture was however, this represents an additional step in the process fl d f period of 11mm Thereafter it was as Well .3 additional reactant, acid losses occur'in T cooled, transferred to a flask fitted with a 6-in. x l-in. recovery and dlstlllatlon System recovery of distillation column packed with glass beads and distilled. the P p p a' q y the Presence of Salts- The water and excess acrylonitrile were removed at at- Recently, It has been discovered that these difliculties mospheflc ressure while the prgduct fi-} (te'rt-n j y1. in the prior art can be obviated to a great extent byremamino)propionitri1e or fl-(tert-pentadecylamino)propioploying water as a catalyst in the addition reaction benitrile, was separated from excess amine under vacuum tween amines which are characterized by steric hindrance (-0-15v mm. of Hg absolute). The yield of product was and the a,/8-unsaturated acid'derivatives to give ,B-aminocalculated in each case. Specific reaction conditions tonitriles and ,B-aminoesters. The use of water as a catalyst gether with the data obtained in the runs are presented provides excellent yields ona comparative basis. How-. in Table I. v

' Table I Mole I Amt of Amino- Aniine/ Percent Solubil- Reaction nitrile' Conver- Amlne Mole 2 Solubllizer izer, Wt. Temp., Product slon, AN 1 Fed Added Percent 0. (g.) Percent ofAmine 10 20 78-81 32.6 66.5 None None 0 79-85 0 0 0 78-82 16.4- 23.4 10 Nilal-dimethylncetam- 7986 26.4 37. 7

1 Acrylonttrlle.

From these data it can be seen that the addition of N,N-disubstituted amides efiects solubilization of water in the higher tert-carbinamines which are characterized by steric hindrance in a system containing these amines, acrylonitrile, and water. By so doing they facilitate the functioning of the water as a catalyst and result insignifi cant increases in yields in the addition reaction of these hindered amines and o e-unsaturated acid derivatives.

Somevariations may be made in reaction conditions from those given in the example without departing from, the scope of the invention. Other suitable amines in addition to those mentioned in the examples which may be reacted according to the process of the invention include, for example, 3-methyl-3-aminohexane, 3-ethyl-3-aminopentane, tert-pentadecylamine, 2-cyclohexyl-2-amino-butane, 2-cyclopentyl-2-aminopropane, '2-ph'eny1-2-a'minopropane, 2-benzyl-2-aminohexane, .2-tolyl-2-aminobutan'e, l,l-di-(p-methylphenyl)-1-aminoethane, l-cycloh'exyl-lbenzyl-l-amino-pr'opane, and the like. Likewise, in addition to those given in the examples, suitable nitriles and lower aliphatic esters of tarp-unsaturated acids include methacrylonitrile, crotononitrile, methyl acrylate, methyl methacrylate, propyl acrylate, ethyl methacrylate, propyl crotonate, methyl crotonate, and the like. Lower aliphatic esters is taken to mean those esters in which the alcohol portions of the ester is an alkyl group containing from 1 to 4 carbon atoms.

While it is preferred to employ stoichiometric quantities of the reactants, quantities in slight excess of the theoretical may be employed. No advantage is seen in using large excesses of either reactant while some difiiculties might be created in certain instances.

The amount of water employed as catalyst may vary over a wide range from as little as 0.1% to as much as 15% by weight of the amine. Preferably, from about 3% to about 10% water provides most effective catalysis of the reaction.

The amount of N,N-disubstituted amide solubilizer to be employed may be varied widely depending upon the amine being reacted and the amount of water employed as catalyst in a specific instance. The optimum quantity is represented by the minimum amount which will effect a completely homogeneous solution of the reactants and the water catalyst. This is readily determinable by observation or by simple testing. Generally, from about 10% to about 100% of the solubilizer by weight of the amine,

reactant is employed.

Any of the N,N-disubstituted amides which are watersoluble are suitable for use as solubilizers; Particularly prefered are the N,N-dialkyls'ubstituted amides. In addition to those mentioned in the examples, other 'disubstituted amides which may be employed include diethylformamide, diethylacetamide, dimethylpropion'amide, diethylproprionamide, dipropylacetamide, and the like.

Generally, the reaction proceeds at temperatures from about room temperature to about 150 C. In some cases, it can be conducted at temperatures as low as C. and as high as 200 C. but in any case reaction temperature is maintained below the decomposition temperatures of the reaction components. At room temperature or below, an extended period of time may be required for reaction, so it is preferred to conduct the reaction at tempera'tures between about 40 and 100 C.

The aminoni-triles produced by the invention are useful aminoesters which comprises reacting a tert-carbinamine of the formula V wherein R, R and R are chosen from the group consisting of alkyl, cycloalkyl, aryl, 'alkaryl, and aralkyl radicals containing from 1 to 12 carbon atoms with a compound selected from the group consisting of the nitriles and lower alkyl esters of acrylic acid, methacrylic acid, and crotonic acid at a temperature in the range from about 0 C. to about 200 C. in the presence of a catalytic quantity of water, said amount of water being in the range from about 0.1% to about 15% by weight 'of the tert-carbinamine and a water-soluble N,N-dialkylamide of a lower unsubstituted monocarboxylic acid in which the alkyl substituents are lower alkyl'groups as a solubilizer therefor, said solubilizer being present in an amount in the I range from about 10% to about 200% by weight of the carbinamine. I

2. The process for producing fl-aminonitriles and flaminoesters which comprises reacting a tert-ca'rbinamine of the formula RR*R"CNH wherein R, R and R are alkyl radicals containing from l to '12 carbon atoms 'with a compound selected from the group consisting ofthe nitrile'sand lower alkyl esters of acrylic acid, metliacrylic acid, and crotonic acid at a temperature in the range from about 0 'C. to about 200 as chemical intermediates. 1 "They may be readily reduced C. in the presence of a catalytic quantity-of water, said amount of water being in the range from about 0.1% to about 15% by weight of the tert-carbinami'ne, and a water-soluble N,N-dialkylamide of a lower unsubstituted monocarboxylic acid in which the alkyl substituents are lower alkylgroups as a solubilizer therefor, said solumili'zer being present in an amount in the range from about 10% to about 200% by weight of the carbinamine. 3-. A process for the production of aminonitriles which comprises reacting a tert-carbinarnine of the formula wherein R, R and R" are alkyl radicals containing from' l to 12 carbon atoms with acrylonitrile at a temperature in the range from about0 C. to-abo'ut 150 C. and "in.

the presence of an amount bfwate'r inthe range from about 0.1% to about 15% by weight of the tert-carbin amine and a water-soluble N,N-dialkyl-amide of a lower unsubstituted monocarboxylic acid in which the 'alkyl substituents are lower alkyl groups as a solubilizer therefor,

said solubilizenbemg present in an amount inv the rangefrom about 10% to about 200% by weight of the carbinamine. v i v 7 4. A process for the production of 18- (tert-nonylamino)- propionitrile which comprises reacting tert-no'nylamine with acrylonitrile at a temperature within the range from about 40 C. to about C. 'in the presence of "an.

amount of Water Within the range from about 3% to abo ut 10% by weight of the nonylamine and as a solubilizer therefor an amount of dimethylformamide in the range j from about 10% to about 200% by weight of said 'nonyl amine.

propionitrile which comprises reacting tert-nonylamine with 'acr'ylonitrile at a temperature within the range from about 40 C. to about 100 C. in the presence of an amount of water within the range from about 3% to about 10% by weight of the nonylamine and as a solubilizer therefor an amount of dimethylacetamide in therange fro'm'about 10% to about 200% by weight of said nonylamine.

6. A process for the production of p-(tert-pentadecyh amino)propionitr-ile which comprises reacting tert-pentadecylarnine with acrylonitrile at a temperature within the range from about 40to about 100 C. in the presence of an amount of water within the range from about 3% to about 10% by weight of the pentadecylamine andas a 1.

solubilizer therefor an amount of dimethylformamide in a solubilizer therefor an amount of dimethylaeetamide in the range from about 10% to about 200% by weight of the range from about 10% to about 200% by weight of said pentadecylamine. said pentadecylamine. 7. A process for the production of p-(tert-pentadecylamino)-propionitrile which comprises reacting tert-penta- 5 References Cited in the file of this patent decylarm'ne with acrylonitrile at a temperature within the range from about 40 to about 100 C. in the presence of UNITED STATES PATENTS an amount of water within the range from about 3% to 1,992,615 Hoffman et a1 Feb. 26, 1935 about 10% by weight of the pentadecylamine and as 2,451,852 McLamore' Oct. 19, 1948 

1. THE PROCESS FOR PRODUCING B-AMINONITRILES AND BAMINOESTERS WHICH COMPRISES REACTING A TERT-CARBINAMINE OF THE FORMULA 